COMMIX-2: A Steady/Unsteady Single-Phase/Two-Phase Three-Dimensional Computer Program for Thermal-Hydraulic Analysis of Reactor Components

摘要

The report describes the numerical procedure of COMMIX-2 for the calculation of steady/unsteady, single-phase/two-phase, three-dimensional fluid flow and heat transfer. The procedure is based on the control-volume approach, which enables the derivation of physically meaningful finite-difference equations. The conservation equations employed are based on a two-fluid model, and this permits the analyses of nonhomogeneous and nonequilibrium flow conditions. The conservation equations of mass, momentum, and energy of each phase are solved as an elliptic system. In addition, the porous-medium formulation with concept of volume porosity, surface permeability, distributed resistance, and distributed heat source is employed and provides a greater range of applicability. The concept of surface permeability is new and greatly facilitates modeling of anisotropic flow and temperature fields.